diff --git a/py/gc.c b/py/gc.c
index 3a3fdb00a5..c319e9ffbf 100644
--- a/py/gc.c
+++ b/py/gc.c
@@ -2,6 +2,7 @@
 #include <string.h>
 
 #include "mpconfig.h"
+#include "misc.h"
 #include "gc.h"
 
 #if MICROPY_ENABLE_GC
diff --git a/tests/basics/string-format.py b/tests/basics/string-format.py
index 290030a9e3..8049c6f73b 100644
--- a/tests/basics/string-format.py
+++ b/tests/basics/string-format.py
@@ -58,6 +58,9 @@ test("{:10.4f}", 123.456)
 test("{:10.4f}", -123.456)
 test("{:10.4g}", 123.456)
 test("{:10.4g}", -123.456)
+test("{:e}", 100)
+test("{:f}", 200)
+test("{:g}", 300)
 
 test("{:10.4E}", 123.456)
 test("{:10.4E}", -123.456)
diff --git a/unix/main.c b/unix/main.c
index 57eaa19976..228c4746a5 100644
--- a/unix/main.c
+++ b/unix/main.c
@@ -6,6 +6,7 @@
 #include <stdarg.h>
 #include <sys/stat.h>
 #include <sys/types.h>
+#include <errno.h>
 
 #include "nlr.h"
 #include "misc.h"
@@ -212,13 +213,24 @@ mp_obj_t test_obj_new(int value) {
     return o;
 }
 
-int usage(void) {
+int usage(char **argv) {
     printf(
-"usage: py [-X <opt>] [-c <command>] [<filename>]\n"
+"usage: %s [-X <opt>] [-c <command>] [<filename>]\n"
 "\n"
-"Implementation specific options:\n"
+"Implementation specific options:\n", argv[0]
+);
+    int impl_opts_cnt = 0;
+#if MICROPY_ENABLE_GC
+    printf(
 "  heapsize=<n> -- set the heap size for the GC\n"
 );
+    impl_opts_cnt++;
+#endif
+
+    if (impl_opts_cnt == 0) {
+        printf("  (none)\n");
+    }
+
     return 1;
 }
 
@@ -249,7 +261,7 @@ void pre_process_options(int argc, char **argv) {
         if (argv[a][0] == '-') {
             if (strcmp(argv[a], "-X") == 0) {
                 if (a + 1 >= argc) {
-                    exit(usage());
+                    exit(usage(argv));
                 }
                 if (0) {
 #if MICROPY_ENABLE_GC
@@ -257,7 +269,7 @@ void pre_process_options(int argc, char **argv) {
                     heap_size = strtol(argv[a + 1] + sizeof("heapsize=") - 1, NULL, 0);
 #endif
                 } else {
-                    exit(usage());
+                    exit(usage(argv));
                 }
                 a++;
             }
@@ -358,7 +370,7 @@ int main(int argc, char **argv) {
         if (argv[a][0] == '-') {
             if (strcmp(argv[a], "-c") == 0) {
                 if (a + 1 >= argc) {
-                    return usage();
+                    return usage(argv);
                 }
                 do_str(argv[a + 1]);
                 executed = true;
@@ -366,16 +378,22 @@ int main(int argc, char **argv) {
             } else if (strcmp(argv[a], "-X") == 0) {
                 a += 1;
             } else {
-                return usage();
+                return usage(argv);
             }
         } else {
-            // Set base dir of the script as first entry in sys.path
             char *basedir = realpath(argv[a], NULL);
-            if (basedir != NULL) {
-                char *p = strrchr(basedir, '/');
-                path_items[0] = MP_OBJ_NEW_QSTR(qstr_from_strn(basedir, p - basedir));
-                free(basedir);
+            if (basedir == NULL) {
+                fprintf(stderr, "%s: can't open file '%s': [Errno %d] ", argv[0], argv[1], errno);
+                perror("");
+                // CPython exits with 2 in such case
+                exit(2);
             }
+
+            // Set base dir of the script as first entry in sys.path
+            char *p = strrchr(basedir, '/');
+            path_items[0] = MP_OBJ_NEW_QSTR(qstr_from_strn(basedir, p - basedir));
+            free(basedir);
+
             for (int i = a; i < argc; i++) {
                 mp_obj_list_append(py_argv, MP_OBJ_NEW_QSTR(qstr_from_str(argv[i])));
             }